蜡样芽胞杆菌905铜锌超氧化物歧化酶基因的克隆及原核表达  

Clone of CuZn-superoxide Dismutase(sodC) Gene from Bacillus cereus 905 and Its Expression in Escherichia coli

作　　者：莫小丹[1] 王勇军[1] 王琦[1] 梅汝鸿[1] 

机构地区：[1]中国农业大学植物病理学系,北京100094

出　　处：《农业生物技术学报》2008年第3期521-525,共5页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金项目(No.30640044);国家高技术研究与发展计划(863)项目(No.2006AA10A211)资助

摘　　要：蜡样芽胞杆菌(Bacillus cereus)905是从小麦(Triticum aestivum)根部分离获得的一株植物有益内生细菌。为从氧自由基毒性角度分析该细菌在植物体内的定殖机制,用PCR方法得到了B.cereus905的超氧化物歧化酶CuZn-SOD基因sodC,该基因由537bp组成,编码179个氨基酸残基。构建表达载体pET-22b-sodC,转化大肠杆菌(Escherichia coli)BL21(DE3),经IPTG诱导表达,该蛋白表现出催化超氧阴离子发生歧化反应的活性,其活性不同程度的受到H2O2和KCN的抑制,验证其为CuZn-SOD。Bacillus cereus strain 905 isolated from wheat （ Triticum aestivum） root is an endophytic beneficial bacterium that can promote the growth of wheat. In this study, the gene encoding CuZn-superoxide dismutase （SOD） in B. cereus 905 was cloned by PCR to illustrate the mechanisms of colonization in plant based on the views of the toxicity of active oxygen species （AOS）. A full-length sodC gene fragment, which composed of 537 bp and coded 179 amino acid residues, was cloned into expression vector pET-22b（＋） and transformed into Escherichia coli BL21 （DE3）. Being induced with IPTG, the protein expressed in E.coli was identified by dying with NBT as one of the SOD kinds and demonstrated that it had CuZn-SOD activity on the basis of inhibited SOD activity by potassium cyanide （KCN） and hydrogen peroxide （H2O2）. SDS-PAGE showed that CuZn-SOD with molecular weight of 23 kD was effectively expressed in E. coli.

关 键 词：蜡样芽胞杆菌 铜锌超氧化物歧化酶 原核表达 

分 类 号：S188[农业科学—农业基础科学]